Accession Number : AD0787634

Title :   Observations on Use of the J Integral to Determine Plane-Strain Fracture Toughness from Subsized Specimens of a Titanium 6Al-4V Alloy.

Descriptive Note : Final rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Yoder,G. R. ; Griffis,C. A.

Report Date : 03 SEP 1974

Pagination or Media Count : 21

Abstract : J-integral procedures were used to obtain resistance curves of J versus crack extension from fatigue-precracked specimens of a titanium 6Al-4V alloy. Specimens of various geometries were employed, all in three-point bending. Crack extensions were delineated by heat tinting. The value of the J integral at the initiation of crack extension, J sub Ic, was determined from the resistance curves and compared with a valid K sub Ic value for this material. Comparison was made of the results obtained with the approximation equation J = 2A/Bb to those obtained with the more cumbersome compliance technique in which the analytical plane-stress solutions of Bucci et al. were used. The range of ratios of crack length to specimen width was examined over which J = 2A/Bb holds, as was the decrease in crack extension at the experimental limit load with increase in ratio of specimen thickness to uncracked ligament. Variation in J sub Ic from specimens cut from different positions through the plate thickness was also explored. (Author)

Descriptors :   *Fracture(Mechanics), *Toughness, *Titanium alloys, Aluminum alloys, Vanadium alloys, Numerical analysis, Graphics, Crack propagation, Plastic properties, Geometric forms

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE